diff options
Diffstat (limited to 'Documentation/virt/kvm')
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 19 | ||||
| -rw-r--r-- | Documentation/virt/kvm/cpuid.rst | 7 | ||||
| -rw-r--r-- | Documentation/virt/kvm/hypercalls.rst | 21 | ||||
| -rw-r--r-- | Documentation/virt/kvm/msr.rst | 13 |
4 files changed, 60 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index cded99561adf..e328caa35d6c 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6950,3 +6950,22 @@ guest according to the bits Hyper-V CPUID feature leaves. Otherwise, all currently implmented Hyper-V features are provided unconditionally when Hyper-V identification is set in the HYPERV_CPUID_INTERFACE (0x40000001) leaf. + +8.34 KVM_CAP_EXIT_HYPERCALL +--------------------------- + +:Capability: KVM_CAP_EXIT_HYPERCALL +:Architectures: x86 +:Type: vm + +This capability, if enabled, will cause KVM to exit to userspace +with KVM_EXIT_HYPERCALL exit reason to process some hypercalls. + +Calling KVM_CHECK_EXTENSION for this capability will return a bitmask +of hypercalls that can be configured to exit to userspace. +Right now, the only such hypercall is KVM_HC_MAP_GPA_RANGE. + +The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset +of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace +the hypercalls whose corresponding bit is in the argument, and return +ENOSYS for the others. diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst index cf62162d4be2..bda3e3e737d7 100644 --- a/Documentation/virt/kvm/cpuid.rst +++ b/Documentation/virt/kvm/cpuid.rst @@ -96,6 +96,13 @@ KVM_FEATURE_MSI_EXT_DEST_ID 15 guest checks this feature bit before using extended destination ID bits in MSI address bits 11-5. +KVM_FEATURE_HC_MAP_GPA_RANGE 16 guest checks this feature bit before + using the map gpa range hypercall + to notify the page state change + +KVM_FEATURE_MIGRATION_CONTROL 17 guest checks this feature bit before + using MSR_KVM_MIGRATION_CONTROL + KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24 host will warn if no guest-side per-cpu warps are expected in kvmclock diff --git a/Documentation/virt/kvm/hypercalls.rst b/Documentation/virt/kvm/hypercalls.rst index ed4fddd364ea..e56fa8b9cfca 100644 --- a/Documentation/virt/kvm/hypercalls.rst +++ b/Documentation/virt/kvm/hypercalls.rst @@ -169,3 +169,24 @@ a0: destination APIC ID :Usage example: When sending a call-function IPI-many to vCPUs, yield if any of the IPI target vCPUs was preempted. + +8. KVM_HC_MAP_GPA_RANGE +------------------------- +:Architecture: x86 +:Status: active +:Purpose: Request KVM to map a GPA range with the specified attributes. + +a0: the guest physical address of the start page +a1: the number of (4kb) pages (must be contiguous in GPA space) +a2: attributes + + Where 'attributes' : + * bits 3:0 - preferred page size encoding 0 = 4kb, 1 = 2mb, 2 = 1gb, etc... + * bit 4 - plaintext = 0, encrypted = 1 + * bits 63:5 - reserved (must be zero) + +**Implementation note**: this hypercall is implemented in userspace via +the KVM_CAP_EXIT_HYPERCALL capability. Userspace must enable that capability +before advertising KVM_FEATURE_HC_MAP_GPA_RANGE in the guest CPUID. In +addition, if the guest supports KVM_FEATURE_MIGRATION_CONTROL, userspace +must also set up an MSR filter to process writes to MSR_KVM_MIGRATION_CONTROL. diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst index e37a14c323d2..9315fc385fb0 100644 --- a/Documentation/virt/kvm/msr.rst +++ b/Documentation/virt/kvm/msr.rst @@ -376,3 +376,16 @@ data: write '1' to bit 0 of the MSR, this causes the host to re-scan its queue and check if there are more notifications pending. The MSR is available if KVM_FEATURE_ASYNC_PF_INT is present in CPUID. + +MSR_KVM_MIGRATION_CONTROL: + 0x4b564d08 + +data: + This MSR is available if KVM_FEATURE_MIGRATION_CONTROL is present in + CPUID. Bit 0 represents whether live migration of the guest is allowed. + + When a guest is started, bit 0 will be 0 if the guest has encrypted + memory and 1 if the guest does not have encrypted memory. If the + guest is communicating page encryption status to the host using the + ``KVM_HC_MAP_GPA_RANGE`` hypercall, it can set bit 0 in this MSR to + allow live migration of the guest. |